According to CNN, it is unclear who Trump is referring to specifically. It could be Deputy Attorney General Rod Rosenstein, who previously wrote a memo recommending that Comey, 56, be fired. However, Rosenstein also approved a special counsel to look into the Russian government’s potential meddling in last year’s presidential election.

As previously reported, Comey testified against Trump on Senate Hill in Washington, D.C., on June 8. In his testimony, Comey claimed that Trump’s comments about agents losing confidence in the FBI were “lies, plain and simple.”

As of now, it is uncertain whether Trump’s tweet was in response to news reports or official notice from the White House. The 45th POTUS also spoke out about the Russia probe in a series of tweets on Friday morning.

“After 7 months of investigations & committee hearings about my ‘collusion with the Russians,’ nobody has been able to show any proof. Sad!” he wrote. “Despite the phony Witch Hunt going on in America, the economic & jobs numbers are great. Regulations way down, jobs and enthusiasm way up!”